As a related art photosensitive cartridge, an image forming unit described in JP-A-2005-114756 includes a photosensitive drum on which an electrostatic latent image is formed, a charger that charges the photosensitive drum, and a developing unit that applies toner to the electrostatic latent image formed on the photosensitive drum, thereby forming a toner image. The toner image is transferred from the photosensitive drum to a recording sheet.
When the toner image is transferred to the recording sheet, paper dust may be adhered to the photosensitive drum from the recording sheet. For this reason, the image forming unit is provided with a paper dust removing device for removing paper dust from the photosensitive drum. The paper dust removing device includes a paper dust container, and a base member that is disposed in the paper dust container so as to be opposed to the photosensitive drum, and in which fibers are planted to catch paper dust on the photosensitive drum. The paper dust container receives the paper dust flying off the fibers.